This invention relates to a multiple needle tufting machine for forming loop pile, and more particularly to a tufting machine incorporating double needle bars and double hook bars.
Multiple needle tufting machines having in-line needles and corresponding loop pile hooks for making loop pile are well known in the art. Moreover, multiple needle tufting machines having staggered needles and correspondingly staggered loop pile hooks are also known in the art.
It is also known in the tufting art to provide pattern attachments for loop pile tufting machine in order to produce tufted patterns having loop pile of different heights.
The Fedevich U.S. Pat. No. 2,889,791, issued June 9, 1959, discloses a "Loop Fabric Stitching Machine" incorporating a front transverse needle bar and a rear transverse needle bar, each supporting corresponding front and rear needles. Although each row of front needles and each row of rear needles in the Fedevich patent is transversely aligned, nevertheless, the front needles are staggered relative to the rear needles. Fedevich further discloses a plurality of transversely aligned front and rear loop pile hooks adapted to cooperate with the corresponding front and rear needles. However, the front and rear hooks or loopers are mounted on corresponding front and rear hook bars, each supported on a separate reciprocable hook shaft so that two hook bars and two hook shafts are required to drive the corresponding front and rear loopers.
The Gebert U.S. Pat. No. 3,025,807, issued Mar. 20, 1962, discloses front and rear needle carriers supporting corresponding needles for alternate penetration of a rearward moving base fabric. Front cut pile hooks and rear loop pile hooks are mounted in transverse rows on a single bracket supported on the same hook shaft or rock shaft for reciprocating the corresponding hooks to alternately engage the corresponding front and rear needles in order to form a front transverse row of cut pile and a rear transverse row of loop pile. Gebert also discloses fabrics in which the cut pile and loop pile are formed at different heights, some of which overlap each other in order to form different patterns.
The Rodstein et al U.S. Pat. No. 3,402,686, issued Sept. 24, 1968, discloses a tufting machine incorporating transverse front and rear needle bars supporting corresponding front and rear needles for simultaneous penetration of the base fabric. A unitary looper incorporating a pair of cut pile hooks longitudinally spaced in the direction of the fabric feed is mounted on a single reciprocable hook shaft for simultaneous cooperation of the double hooks with the front and rear needles in order to simultaneously form in the base fabric a pair of transverse rows of, longitudinally spaced cut pile tufts. The front and rear needles disclosed in the Rodstein patent are longitudinally aligned in the direction of fabric feed, as well as being transversely aligned in their respective front and rear rows.
However, none of the above patents, or other prior art known to the Applicant, includes a pair of front and rear transverse needle bars and a pair of corresponding front and rear hook bars adapted to be adjusted relative to each other in a direction transverse to the direction of the fabric feed, to simultaneously form a front row of loop pile and a rear row of loop pile in which the loops are either in longitudinal alignment in the direction of the fabric feed, or are staggered, depending upon the adjustment of the respective needle bars and hook bars.